1. Field of the Invention
The present invention relates to a mounting structure of a chip component, and in particular, relates to a mounting structure of a chip component in which it is possible to mitigate a decrease in bonding strength of a thin chip component.
2. Description of Related Art
In recent years, demand has increased for miniaturization and an increase in density for chip components, and various problems have become apparent as chip components have become miniaturized and as the density thereof has increased. Refer to Patent Document 1, for example. In Patent Document 1, the gap between terminals is set to be narrower than the gap between lands in order to make the chip component connected to lands provided on a printed circuit board not susceptible to being separated from the printed circuit board after being mounted, thus improving connective reliability. As a result, solder portions are connected to the terminals of the chip component while being inclined at acute angles in relation to a plane extending from one land to the opposite land, and thus, the chip component has a greater resistance to being separated from the printed circuit board.
However, problems that need to be addressed as chip components are miniaturized and the density thereof is increased are not limited to the above-mentioned problem. For example, increased density results in various problems such as bridging, component misalignment, open solder defect, missing parts, solder balling, tombstoning, and IC damage, due to the particle size of the solder paste becoming smaller or the space between components becoming narrower.
Refer to Patent Document 2, for example. In Patent Document 2, in order to ensure sufficient strength in a solder bonding portion and prevent solder melting defects, a solder resist in the bonding surface vicinity portion for lands to be soldered is given a pattern in which an opening narrower than the short side of a chip component is provided in the shorter side direction of the chip component between the left and right lands on the substrate to which the chip component is to be connected, and the pattern having this opening between the lands is formed such that the width of the opening becomes wider in directions opposite to the center between the left and right lands.
Refer to Patent Document 3. In Patent Document 3, in order to mitigate the occurrence of solder balling and to prevent misalignment and tombstoning of the chip component, each of the pair of lands on the printed circuit board is constituted of an electrode mounting portion, an outer overhang portion, and an inner overhang portion, and the amount of overhang for the outer overhang portion is set to ¼ the width of the electrode mounting portion, while the amount of overhang for the inner overhang portion is set to ⅕ the width of the electrode mounting portion.